This invention relates to brake systems, and more particularly relates to a brake for roller skates, although not limited to only roller skates.
A skater using in-line roller skates must be able to safely stop or slow down regardless of his/her expertise, and further must always be "in control," so that they do not risk running into other skaters or bystanders. Beginners, in particular, have problems as they are learning to skate due to the free running nature of roller skates. However, more experienced skaters also desire fine levels of control to facilitate quick turns and stops. A number of roller skate brakes have been constructed for these purposes. However, known roller skate brakes have several problems as noted below.
The most common braking system now used on in-line roller skates includes a wear block attached to a rear of the skate that can be dragged on a skating surface to provide a braking action. However, the wear block rapidly wears away, and thus has a limited life. Further, the wear block is subject to catching or hooking on depressions, such as on the edges of or depressions in concrete sections in a sidewalk, such that the user may trip and fall. Still further, a wear block will often pick up small stones that embed themselves in the wear block. These small stones dramatically change the coefficient of friction generated by the wear block as the wear block is dragged on the skating surface, thus causing the brake to provide an uncertain and inconsistent brake force. Still further, the tilt angle of the roller skate to engage the wear block with the ground changes as the wear block becomes worn, thus creating uncertainty as to when or how much braking force will result from an attempt to brake.
Some in-line roller skate brakes apply a braking force to one or more of the "active" weight-supporting wheels on the skate. For example, see U.S. Pat. No. 5,232,231 to Carlsmith. However, if any of these "active" weight-supporting wheels lockup or skid, a flat spot is created on the wheel. This flat spot causes the roller skate to vibrate during use, which is very annoying and also physically tiring. Further, the vibration caused by an "active" wheel having a flat spot takes away tremendously from the enjoyment of skating. Notably, the "active" wheels on the in-line roller skates periodically support less than an equal portion of a person's weight due to unevenness of the skating surface. Thus, it is relatively common for an "active" wheel that is being braked to skid and develop a flat spot.
Another problem is that brakes sometimes stick or drag, thus causing a skater to unknowingly expend extra effort when skating.
U.S. Pat. No. 5,183,275 to Hoskin discloses a roller skate brake including a brake pad and a roller for engaging the braking pad. However, the actuating mechanism in Hoskin Pat. No. 5,183,275 involves multiple links and a braking wheel that are relatively small and intricate, such that they are mechanically more delicate and expensive to manufacture and assemble than are desired, and also that are connected in a way that is potentially not as reliable and consistent in operation as is desired. Further, in Hoskin Pat. No. 5,183,275, the braking wheel, in addition to engaging the brake pad, also engages the rear in-line weight-bearing wheel on the roller skate, thus leading to the problem of flat spots previously discussed above.
U.S. Pat. No. 5,192,099 to Riutta discloses a roller skate including a brake pad and a rear skate wheel mounted on flexible side members that flex, so that the rear skate wheel can be moved into engagement with the brake pad. The brake pad is adjustable to various fixed positions along a slot to compensate for wheel and brake pad wear. However, the problem of flat spots on wheels is not addressed. Also, the flexibility of the side members brings the durability and mechanical stability of the side members into question since, if the side members are vertically flexible along a "long" side of the cross section, they would tend to permit lateral movement and wandering of the rear wheel.
U.S. Pat. No. 5,088,748 to Koselka discloses in FIG. 1 a braking system in which a braking wheel and braking member are pivotally mounted to the roller skate by a four-bar linkage. As a practical matter, the multiple joints in the linkages are difficult to manufacture so that they operate freely yet without sloppiness. Further, even if manufactured properly, the joints are likely to loosen over time. Still further, the braking member operates on the hub of the braking wheel, such that the torque arm is small and the frictional braking force must be quite large in order to generate a desired level of braking torque on the braking wheel. Also, the device lacks adjustability. The embodiments in FIGS. 4 and 5 do not have the four-bar linkage, but rather have a pair of trailing arms supporting a braking wheel. However, the braking member operates to brake the rear weight-supporting wheel on the roller skate, thus leading to the problem of flat spots discussed above.
U.S. Pat. Nos. 4,453,726 and 4,402,520 to Ziegler disclose traditional four-wheeled roller skates where the wheels are arranged in a rectangular pattern. The roller skates include a braking wheel that cams pressure elements outwardly against two axially aligned roller wheels. Notably, the camming action tends to force the wheels apart, such that the bearings on the rear skate wheels may need constant maintenance or may fail prematurely. Further, it is noted that major modifications would be required to apply the braking system in Ziegler to an in-line roller skate.
U.S. Pat. No. 4,275,895 to Edwards discloses a cuff-actuated braking system including a brake pad that engages the two rear wheels of a rectangularly arranged, four-wheel skate. (See FIG. 3.) Notably, the brake pad engages the rear wheels, and thus flat spots and wheel wear can be a problem. Also, major modifications would be required to apply the braking system in Edwards to an in-line roller skate.
U.S. Pat. No. 2,027,487 to Means discloses a brake pad attached to a flexible support that can be flexed to engage the brake pad with the rear roller skate. In addition to the problems previously discussed relating to rear wheel flat spots and wear, major modification is required to use the device on in-line roller skates.
Aside from the above, the known roller skate brakes do not provide a natural and smooth "feel" to the skater when braking. I have not determined exactly why this is true, but I believe it to be due in part inherent characteristics in many of the prior art brakes, and the inability of the known constructions to provide a consistent and predictable braking force that increases in a manner directly correlated to the amount of force transmitted from the skate-supporting surface to the brake. Also, it is noted that many of the prior art brakes are expensive to manufacture, are expensive to maintain, and also are difficult to adjust and/or keep in adjustment.
As noted above, most roller skates are braked by biasing a wear-resistant slide block against a floor surface, with the amount of braking force depending on the friction generated by the slide block as it is dragged across the floor surface. A problem with the slide block is that the braking force is inconsistent, and further the brake does not hit the ground at the same time as the slide block wears down. With a rolling brake wheel of the present invention, the wheel maintains continuous contact with the floor surface and does not slide, nor does the present brake wheel wear away as fast as a slide block. Instead, the amount of friction for braking comes from the amount of force generated to bias a brake shoe or other braking component against the rotating brake wheel or its hub. The frictional force for breaking loose the braking wheel from the floor surface is normally never exceeded. This is intentionally done so that the braking wheel does not slide and in turn does not develop flat spots, and further so that the braking wheel does not wear out as quickly.
However, even though it is important not to brake a braking wheel so hard as to cause it to slide, my testing has also shown that it is sometimes desirable to amplify the amount of force generated against a braking wheel as a skater leans rearwardly as one way of adding control to the person skating. For example, by biasing the brake shoe with mechanical advantage, a skater can control the braking force with greater finesse and with less "brute force." More specifically, my testing has shown that, with sufficient mechanical advantage, a rear end of the person's skate can be lifted off of the floor surface with the entire person's weight supported only by the front wheel of the skate and the rear braking wheel. This position provides the maximum amount of force that a skater can apply to a skate brake while still maintaining wheel contact with the ground. A non-linear braking force is also sometimes desirable where a continuously linearly increasing force applied by a skater results in an exponentially increasing braking force.
Another problem in the prior art is attachment of brake components to the skate's wheeled frame. Separate fasteners that require tools for removal can be frustrating to remove because proper tools are not available or the skater is not good at using the tools. Further, the separate fasteners can be lost.
Thus, braking systems for in-line roller skates and other wheel constructions solving the aforementioned problems are desired.